Core B, Data Management and Biostatistical Analysis, for this Program Project provides a centralized resource, services and skill essential for successful completion of the component projects. Specifically, this Core provides for a centralized computing facility with direct electronic linkage to all participating component projects. Furthermore, Core B provides resources and personnel data management and quality control, as well as biostatistical support. The core team brings together a group of highly skilled technical personnel with extensive experience in managing and analyzing large epidemiologic datasets. The core will be led by Drs. Roins and Tolbert. Drs. Christiani and Monson are intimately involved as co-investigators and will further contribute to program integration.